1. FIELD OF THE INVENTION
In general, the present invention is related to high speed fluidic fire extinguishing devices and more particularly to a device and system for equally distributing fire extinguishing agent with the expellant gas. The fluid is received at unequal cross-sectional density due to a change of direction upstream of the system. The fluid is then rotated and directed into a tee downstream of the system, where it becomes symmetrically divided by the tee thereby producing a equal flow through each leg of the tee.
2. DESCRIPTION OF PRIOR ART
Heretofore, devices were incorporated in fire extinguishing systems which encountered separation of expellant gas and the fire extinguishing agent due to changes in direction of flow upstream of the system. In high speed fluidics, especially when using fire extinguishing agents that are denser than the expellant gas, there is a disassociation of the fire extinguishing agent and the expellant gas due to centrifugal force, as the fluid is propelled around an elbow. To provide for proper distribution of the fire extinguishing agent upon splitting the stream, at a tee, a minimum length of pipe was used between said tee and the elbow at which section the change of direction of flow took place. This produced a design restriction which limited installations since usually there was not enough room to provide for these minimum lengths of pipe as required.
Usually these systems were used in high speed fluidic fire extinguishing equipment installed in food establishments or industrial fire hazards. There is a limited area over a plurality of fire hazards each of which requires at least one fire extinguishing nozzle. To reach these nozzles the system utilized a plurality of elbows and tees. At each elbow the higher density fire extinguishing agent, due to the high speed and centrifugal force, will accumulate at the outer area of the elbow and the expellant gas remained in the inner area, due to the differential of their density. The restriction of space creates difficulties since in field installations of extinguishing systems there is no room to install a run of pipe to accommodate all of the fire nozzles needed to properly deploy the extinguishing agent evenly over the entire hazard.
Further attempts made in providing a "venturi" type pipe section. The non-homogeneous mixture of the fire extinguishing agent and expellant gas coming from a change of direction, as an elbow in a fire extinguishing system, would go into the venturi and be forced back together by the restriction of the venturi orifice. The venturi works on two principles concurrently. First the funnelling down to a smaller diameter will tend to cause the pipe to fill up with the fire extinguishing agent on the threshold of the venturi. Secondly, once the fire extinguishing agent gets to the venturi, its speed is increased. The increase of the speed inside the venturi increases the frictional forces on the fire extinguishing agent and may contribute to its mixing.
There are several difficulties encountered in the use of the venturi. First, although it may minimize the necessity of using a length of pipe between the elbow and the tee it does introduce a significant pressure drop. Second, the amount of restriction inherently necessary in the venturi which is necessary to thoroughly mix the fire extinguishing agent and gas mixture, depends on how full the preceding pipe may be. If the pipe is near the extinguishing system's storage pressure tank it will be full of the fire extinguishing agent and hence a small reduction in the inside diameter of the pipe may be adequate. If the venturi is at the end of several yokes in the system then the pipe will never be completely filled, necessitating greater restriction in the venturi. This will also necessitate the use of different sized venturies making installing more laborious and expensive. Since the fire extinguishing agent's extinguishing ability is directly proportional to the flow rate, any resulting lengthening of time of discharge, because of diameter restrictions, reduces extinguishing potential.
The present invention solves these problems and specifically the space problem to a large extent by eliminating the necessity of using any length of pipe between the elbows and the tees. Secondly, it does not create pressure drops, therefore, the present invention will permit more flexibility in the use of extra length of pipe for producing a more efficient fire extinguishing system. Proper distribution is developed by a rotation of the fire extinguishing agent and expellant gas by the steering device so that an equal proportion of the fire extinguishing agent and expellant gas travels through each leg of the tee.